From: Geert Nijs (geert.nijs@simac.be)
Date: Thu Sep 29 2005 - 10:54:04 GMT-3
Kevin, this would also be a solution for that problem i know ! :-).
But that is not my main reason. The reason i want to implement this is
that one hop further from R1 and R2, there are routers R3 and R4 and
they are running ip verify unicast and do not allow assymetric routing.
So at this point, when hsrp switches, the routing must be manually
adjusted so that ip verify unicast does not start dropping packets. The
situation is a bit complicated to explain in short. If router R1
completely fails, there is no problem, but if someone - by accident -
changes the HSRP priorities in an attempt to solve other problems - and
forgets to also change the routing metrics, we are in big problems :-)
I am trying to keep symmetric routing automatically when hsrp switches
(caused by for example someone who configures a higher prio). Ideally as
long as R1 is HSRP active, only R1 should be announcing the LAN1 subnet.
When R2 becomes active (for whatever reason), R2 should start
advertising the LAN1 subnet or start advertising a route with a lower
metric..
I really miss this kind of functionality in a Cisco router.
The problem is that you cant 'track' the state of an HSRP router. Is
there a way to use the track functionality for this ?
There is also something like HSRP redundancy group which is used by
static NAT, so that as long as HSRP is not active, the router does not
inject static nat entries in its table and mac cache. This is the only
thing i know of that keeps an eye on the hsrp state......
regards,
Geert
-----Original Message-----
From: kgannon@gmail.com [mailto:kgannon@gmail.com] On Behalf Of kevin
gannon
Sent: donderdag 29 september 2005 14:10
To: Leigh Harrison
Cc: Geert Nijs; ccielab@groupstudy.com
Subject: Re: changing incoming routing based on vrrp/hsrp
By chance are you trying to stop flooding in a switched environment due
to asymetric routing ?
Regards
Kevin
On 9/29/05, Leigh Harrison <ccileigh@gmail.com> wrote:
> Geert,
>
> Very interesting this one. My first thought is to use the hsrp
> address of the routers as the gateway into LAN 1. But this depends on
> why you want to make the different routers hsrp master.
>
> From that, my second though would be to use the global "track"
> command and track on, say, a routes metric value, give it a threshold
> and switch over if it's not the best route in.
>
> What would be your reason for cutting over in hrsp/vrrp ?
>
> LH
>
> Geert Nijs wrote:
>
> >Hi all,
> >
> >I am looking for a way to change incoming packets based on which
> >router is HSRP active, in the following topology:
> >
> >| |
> >| |
> >R1 R2
> >| |
> >-------LAN 1 -----------
> >
> >
> >Router R1 and R2 are running VRRP or HSRP for LAN 1 If R1 is HSRP
> >master, i want packets for LAN1 to come in via R1 If R2 becomes HSRP
> >master, i want packets for LAN1 to come in via R2 This can be done by
> >changing the routing metric of the R1 and R2 uplinks or by
> >configuring R1 and R2 in such a way that it wil not advertise LAN1
> >when it is HSRP slave, but how to do this automatically ??
> >
> >Anyone an idea on how to accomplish this..........mmm..there must be
> >a way....
> >
> >
> >regards,
> >
> >Geert Nijs
> >CCIE #13729
> >
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